1. Field
The present disclosure relates generally to electromechanical motors and, in particular, to reluctance motors. Still more particularly, the present disclosure relates to reluctance motors capable of converting electrical power into mechanical power with reduced torque ripple using a reduced number of magnetic poles.
2. Background
A reluctance motor is a type of electromechanical motor that runs by magnetic reluctance. In particular, with the concept of magnetic reluctance, a magnetic field causes magnetic flux to follow the path of least magnetic reluctance. Currently available reluctance motors typically include a stator and a rotor. Both the stator and the rotor have magnetic poles. Typically, the stator consists of electromagnetic coils arranged about a center axis in a manner that forms magnetic pole pairs. When these magnetic pole pairs are energized, a rotating magnetic field is created. This rotating magnetic field causes the magnetic poles of the rotor to move along the path of least magnetic reluctance.
While reluctance motors provide high power density at low cost, these types of motors may operate with higher torque ripple than desired. Torque ripple is the difference between the maximum torque and the minimum torque produced during one revolution. Further, higher torque ripples of these types of motors may create more noise than desired.
A switched reluctance motor is one type of reluctance motor. Switched reluctance motors have rotors with fewer magnetic poles than the magnetic poles on the stator. The magnetic poles of the stator may be referred to as stator poles and the magnetic poles of the rotor may be referred to as rotor poles. Typical switched reluctance motors have six stator poles and four rotor poles. While this configuration may reduce torque ripple, torque ripple may not be reduced to within desired tolerances for certain applications.
Currently available reluctance motors may be unable to provide torque ripple that is sufficiently low to meet selected requirements for systems such as, but not limited to, aerospace systems. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.